Nurses, intensive care personnel, respiratory therapists, emergency room staff, paramedics, chemists, and other clinicians have certain things that they do all the time which must be done properly otherwise there may be serious consequences up to and including the death of a patient.
An example relates to drug and infusion calculations. A doctor issues prescriptions to clinicians based on the body weight of the patient since different size people take different amounts of drugs. A clinician must then get the drug from the pharmacy which provides it at a standard concentration and, looking at the order from a doctor and patient information on body weight, calculate precisely how much medication to give over a certain period of time. Sometimes, the dosages are based on body surface area and require further calculations and constants.
The calculations are often complex and require specific constants for dosages and infusions. Very experienced clinicians who have long experience will have memorized the constants, but newer clinicians or those who do not routinely work in the area will have to lookup the constants in a reference book in addition to performing the complex calculations. Thus, in addition to handheld calculators, these people usually must carry around little reference booklets which must fit the pockets in their lab coats.
In some cases where the prescriptions are routine, the clinicians will be provided with small charts to look up how much medication to give for a given body weight. However, even this is of limited value since many drugs are provided in solution at a specific concentration per volume of fluid, or a specific mass per tablet. A clinician must then compute the correct total dose for a patient. These calculations must often be performed with dimensioned units which must be converted into other comparable units in order to perform the calculations. For example, the prescription could be in terms of so many micrograms per square meter of body surface, while the drug concentration could be in milligrams per cubic centimeter. A mistake in the decimal point could kill a patient.
For some areas of medicine, a clinician will be told by a doctor to obtain certain medical data about a patient which are calculated from other parameters. These calculations are complex and often difficult to perform. An easy method to calculate these important parameters would benefit patient treatment. Cardiac, hemodynamic, respiratory and ventilatory calculations often fall into this category.
Another example is if a patient has been poisoned, and it is necessary to determine how long it takes for the toxins to wear off and how the patient is responding to treatment. There are complex relationships involved for which various nomograms have been developed for various toxins where observations are required over a timeframe.
Acid-base disorders also require complex calculations with several independent variables. These calculations in turn are often difficult to use and introduce mistakes into the treatment process.
For all health care professionals, handy drug references have long been desirable, but a comprehensive reference has had to be extremely bulky because of all the information and cross-references required. Computerized references have also been more convenient in laptop form, but the cross-referencing systems have made them difficult to use. Also, computers are not always available for clinicians. It is often not convenient to use laptop computers in a clinical setting, and they are relatively costly when compared to the cost of handheld calculators.
In the medical field, it is further necessary to have readily available the many different values of what constitutes the norm of the human physiology to determine how far off a patient is from normal. These values must be constantly referred to such that the small reference books regularly fall apart, become hard to read, and must be constantly replaced. Thus, a hand size reference has long been sought which provides easy accessibility and convenience.
A comprehensive solution for clinicians has long been sought which would ease their workload, simplify the complexity of the things they do, and reduce the life threatening errors, but such a solution has long eluded those skilled in the art.